Atomic Physics with Highly-Charged Ions at the Facility for Heavy-Ion and Antiproton Research (FAIR).

The new facility at GSI has key features that offer a range of new opportunities in atomic physics and related fields. First, high-charge state ions moving at velocities close to the speed of light generate electric and magnetic fields of exceptional strength. Second, at those relativistic velocities, the energies of optical transitions, such as for lasers, are boosted to the x-ray region. The strong fields carried by heavy, highly-charged ions are their outstanding attributes for atomic and applied physics research. Together with anticipated high beam intensities a range of important experiments is envisioned.

In relativistic, high-Z ion-atom collisions, extremely intense photon fields arise due to both, the high nuclear charges and the extremely high velocities. This will even lead to the creation of real particle-antiparticle pairs (e.g. e+-e). For the heaviest ions, Quantum ElectroDynamics (QED), the Standard Model of electromagnetism and a basis of modern physics, will be probed near the critical field limit associated with the extreme conditions of high charge states and high velocities. The fields present in highly relativistic collisions are strong enough to produce real e+-e- pairs directly out of the vacuum. Precision studies of QED in bound states will be possible through the large Doppler shifts of highly relativistic ions which generate extreme energy shifts for photons in the ion rest frame. As a consequence, even the heaviest few-electron ions can now be studied in precision QED experiments by using state of the art laser systems. The Doppler effect will also be used for the first time for laser cooling of heavy, highly-charged ions, promising beams at relativistic energies and brilliances that are suited for unique precision studies in atomic and nuclear physics. Moreover, the interaction of relativistic, highly-charged heavy ions with matter provides new possibilities in applications, in particular in material modifications and tests as well as in biophysics and space research.